Abstract：Due to the factory wet ,old electrical wire ,bad electrical wire, it will result in short circuit to the ground ,at last result in dextral electric current. this design use electrical sensor to inspect the current, and convert the signal what had inspect ,then sent it to the major controller at89c55 ,when the current over number we had set ,it will generate light and sound and break the electrical , in order to ensure the safety of the electrical. this design provide hardware design, software design, and simulate, the result is good.
Keywords：Open Circuit Protect; galvanoscopic; AT89C55; ADC0808; LED display
